Vacuum systems find wide applications in research, education, product development, and production. Typical systems comprise independent and interchangeable components. Such components may include testing chambers, pumps, gauges, valves, specimen manipulators, testing apparatus, radiation sources, particle detectors, heating and cooling systems, and other components known in the industry.
Processes or experiments that require high or ultra-high vacuum (UHV) currently employ all metal vacuum joints. A typical flange 20 for an all-metal joint is illustrated in FIG. 1. Such a joint is comprised of at least two flanges 20, 24 illustrated in FIG. 2. Each of the flanges 20, 24 includes an annular recess 26, 28 and an annular knife edge 30, 32. The flanges 20, 24 are configured for mating using a soft, metallic gasket 34 (e.g. a copper gasket). The opposing knife edges 30, 32 are pressed into the gasket 34 when the flanges 20, 24 are compressed together by tightening bolts 38. The knife edges 30, 32 in combination with the gasket 34 form a UHV seal.
The force of the tightened bolts 38 is transferred to the gasket 34 through the thickness of the flanges 20, 24. The bolt holes 36 are disposed on a diameter that is outside that of the knife edge 30, 32. If the standard flange 20, 24 is not of appropriate thickness, the flanges 20, 24 may deform as depicted in FIGS. 3 and 4. The deformed flange 25A in FIG. 3 is considered a dish-shaped deformation and results from the flange 25A bowing around the perimeter of the gasket. The deformed flange 25B in FIG. 4 is a wave-like deformation and results from deflection of the flange 25B between bolts in the all-metal joint. The bowing of the flange 25A occurs due to the moment arm between the knife edge 30, 32 and the bolt 38. In the case of a deflection or deformation, such as those illustrated in FIGS. 3 and 4, the seal may leak if the force placed on the gasket 34 between the adjacent bolts 38 is less than the force required to press the knife edges 30, 32 sufficiently into the gasket 34 to form a seal. Only an appropriate thickness of the flange provides adequate resistance to deformation in this situation.
Thus, a heretofore unaddressed need exists in the industry to address the aforementioned deficiencies and inadequacies.